TY - JOUR
T1 - Effects of 3,4-methylenedioxymethamphetamine and related amphetamines on autonomic and behavioral thermoregulation
AU - Jaehne, Emily J.
AU - Salem, Abdallah
AU - Irvine, Rodney J.
N1 - Funding Information:
The authors acknowledge the assistance of Paul Callaghan, Jessica Phillips and Lydia Rofe on pilot experiments leading to this work. They also thank the National Health and Medical Research Council of Australia for their financial support.
PY - 2005/7
Y1 - 2005/7
N2 - 3,4-Methylenedioxymethamphetamine (MDMA, 'ecstasy') and related amphetamines such as para-methoxyamphetamine (PMA) disrupt normal thermoregulation in humans and rats. Behavior, an important component of thermoregulation in mammals, has not been investigated with respect to these drugs. This is surprising as harm minimization depends on appropriate thermoregulatory behavior by drug users. The effects of MDMA (10 mg/kg), PMA (10 mg/kg) and d-amphetamine (2 mg/kg) were therefore studied in Sprague-Dawley rats, with telemetry implants measuring core body temperature (TC), locomotor activity and heart rate. Rats were administered an amphetamine or saline and confined to an ambient temperature of 21, 30 or 15°C for 30 min, before being able to choose their preferred temperature (TP) on a thermally graded runway (11-41°C). Confinement at 21°C had little effect on TC in any group. At 30°C MDMA and PMA increased TC compared to saline (p < 0.001). MDMA treated animals behaviorally overcompensated for this effect (p < 0.01). Locomotor activity after MDMA treatment was significantly elevated compared with saline (p < 0.01). In contrast, at 15°C MDMA administration resulted in a lower TC than saline (p < 0.001). MDMA and PMA disrupt autonomic components of thermoregulation, while behavioral components are disrupted to a lesser extent. These results highlight differences in thermoregulatory responses to individual drugs, which were only evident when behavior was measured, and this may be important in assessing their risk.
AB - 3,4-Methylenedioxymethamphetamine (MDMA, 'ecstasy') and related amphetamines such as para-methoxyamphetamine (PMA) disrupt normal thermoregulation in humans and rats. Behavior, an important component of thermoregulation in mammals, has not been investigated with respect to these drugs. This is surprising as harm minimization depends on appropriate thermoregulatory behavior by drug users. The effects of MDMA (10 mg/kg), PMA (10 mg/kg) and d-amphetamine (2 mg/kg) were therefore studied in Sprague-Dawley rats, with telemetry implants measuring core body temperature (TC), locomotor activity and heart rate. Rats were administered an amphetamine or saline and confined to an ambient temperature of 21, 30 or 15°C for 30 min, before being able to choose their preferred temperature (TP) on a thermally graded runway (11-41°C). Confinement at 21°C had little effect on TC in any group. At 30°C MDMA and PMA increased TC compared to saline (p < 0.001). MDMA treated animals behaviorally overcompensated for this effect (p < 0.01). Locomotor activity after MDMA treatment was significantly elevated compared with saline (p < 0.01). In contrast, at 15°C MDMA administration resulted in a lower TC than saline (p < 0.001). MDMA and PMA disrupt autonomic components of thermoregulation, while behavioral components are disrupted to a lesser extent. These results highlight differences in thermoregulatory responses to individual drugs, which were only evident when behavior was measured, and this may be important in assessing their risk.
KW - 3,4-Methylenedioxymethamphetamine
KW - Behavior
KW - Ecstasy
KW - Para-methoxyamphetamine
KW - Telemetry
KW - Thermoregulation
UR - http://www.scopus.com/inward/record.url?scp=22044442834&partnerID=8YFLogxK
U2 - 10.1016/j.pbb.2005.04.005
DO - 10.1016/j.pbb.2005.04.005
M3 - Article
C2 - 15904952
AN - SCOPUS:22044442834
SN - 0091-3057
VL - 81
SP - 485
EP - 496
JO - Pharmacology Biochemistry and Behavior
JF - Pharmacology Biochemistry and Behavior
IS - 3
ER -